The present invention relates to vehicle navigation systems. More specifically, the present invention provides fast and easy-to-use methods and apparatus for selecting an entry from a list of entries where the list is representative of a large database file. Still more specifically, a graphical user interface for a vehicle navigation system is described herein which facilitates selection of a geographical feature such as, for example, a city, street, highway, or point of interest, for the purpose of route generation.
To enhance the desirability and effectiveness of vehicle navigation systems, user interaction with the such systems must be made convenient and easy to understand. For example, the way in which a user selects a destination for route generation should be self explanatory as well as fast to prevent the user from becoming frustrated. This is especially true in view of the fact that map database files in vehicle navigation systems continue to grow as the geography of more and more regions of the world become more fully digitized. That is, for example, the number of available cities which may be presented to the user in a single list has increased dramatically in recent years. Not only is it tiresome and frustrating to scroll sequentially through the entirety of such a list, it may also present a safety hazard if the driver attempts to select an entry while the vehicle is moving.
In addition, because the display screen represents a significant component of the cost of a vehicle navigation system, smaller (and therefore less expensive) screens are desirable to make the widespread distribution of such systems economically feasible. However, smaller screens impose limits on the number of objects which can be simultaneously presented and therefore on the manner in which a selection algorithm may be implemented. For example, with a 3" screen, only a small number of the entries from a list of cities may be displayed at any given time. In such a case, a page-up/page-down function is typically not sufficient to traverse the list quickly enough to satisfy most users.
As an alternative, an array of alphanumeric characters might be presented from which the user may generate a string of characters which may then be used to jump either directly to or at least closer to an entry corresponding to the string. Unfortunately, for such an array of characters to be sufficiently visible to a user it would need to take up a considerable portion of the display screen, thus taking up space which would otherwise be used to present the list itself. Thus, as the screen size decreases, the practicality of such a solution diminishes. Ultimately, the graphical user interface employed to implement a selection process must strike a balance between the number and size of objects necessary to implement the process such that the objects are clearly visible and the process is sufficiently easy to follow for the typical user.
It is therefore desirable for providers of vehicle navigation systems to provide techniques by which a user may get to a desired entry in a large list without having to traverse all of the entries in the entire database file. It is also desirable that such techniques have simple and visually appealing implementations which may be presented on relatively small display screens.
Another disadvantage of currently available navigation systems is also associated with the manner in which a destination is selected. Specifically, when the user wants to designate the destination by its street address or by a street intersection, the user must typically first identify the city before selecting the street or the address. However, when the user is unfamiliar with the local geography, as is often the case, this may be a difficult task.
It is therefore desirable that the manner in which a destination is selected in a vehicle navigation system be sufficiently flexible to account for the different levels of familiarity among users with the geographic regions in which the system is operating.